Planetary Gear Description: Operation: Notes

• The planetary gear works as a transmission when the sun gear and the internal gear are engaged.
• The sun gear, installed inside of the pinion gears, and the internal gear, installed outside of the pinion gears, are engaged with their respective gears.
• The sun gear and the internal gear rotate on the center of the planetary gear.
  Fig 1: Identifying Planetary Gear Components

  Courtesy of MAZDA MOTORS CORP.
• The pinion gears turn in the following two ways:
  • On their own centers ("rotation").
  • On the center of the planetary gear ("revolution").
    Fig 2: Identifying Pinion Gear Rotation

    Courtesy of MAZDA MOTORS CORP.